installing a mini split a.c. system I'm about to order my system and I need to gather details on installing this into a MCI 8 bus. Pics and details would be very helpful...any other tips would also be appreciated!

Just did a nice long post the before end Carpenter Bus sales took over the screen and deleted it. Now short version. How may? Old condenser bay open? Have you bought them yet? what kind? Install: All lines anchor firm & insulated. I sit evap a little off level to drain end to aid in condensate drain. Your first name would be good? Inverter type is my preferred type. Bob

Part 2: have use part of center bay partitioned off with mesh inside of part of the removed (cut out) door skin.Need a place for the condenser that it will be oil free and firmly mounted. I used the spare tire compartment for one of mine in the 98 build. Just need to create air flow. I don't know if you can stand one up in a MCI ;it's been awhile since I have been in one.(9000btu unit) condenser fit in Prevost. Bob

part three. I mentioned inverter type: a little more up front but much more bang for the buck in the end. heat and air heat works down to 10F (I have this in my home also) Supper low amp load in comparison. The 9000btu is rated at 6amps and that includes start up and the 12000btu at alittle over 8 amps--big numbers if you are on gen sets or minimum power. Also consider using more than one unit (if needed) than going to a larger 220 unit. I have 2 ea 9000 and a 12000 not needed but have back up and zoned usage and all run on 110volt. Bob

I have a 77 mci 8 that has the old evaporator bay cleared out completely (under and just behind driver. I plan on buying a 3 zone 32k BTU heat pump inverter unit that uses r410. I'm not concerned on using a 220 unit since I have a 10k diesel genset and the bus is basicley a day coach.

Jerry; I have a 24,000 @208 doing my whole house 2600sq ft in SW Ind 100 plus last summer. FWIW. Need to ck measurements on the condenser cabinet for that larger unit and make sure it will fit in that bay. I have a Evap above driver one about half way and one in bedroom. All three about 1ft off ceiling. The sweep feature will move the air from top to bottom to prevent layering. My coach has a raised roof. So get your as high as possible but leave at least 8inches from ceiling. I ran condensate tube for front down center post with other lines and into spare tire compartment. Down the center of your MCI there is a utility tunnel that runs from the spare tire compartment to the rear of the last baggage bay. Have you removed the Air/heater duct along sides(common practice) if not that area could be used. Some one had pic posted last year of a 8 or 9 with the floor out with that duct space exposed. That would be a great help to you! Will ck some more as I remember MCI details. I made steel mounting brackets to span stock frame then bolted supplied mounting bracket for inside unit to them. Bob

24,000btu outdoor unit 35 inches tall by 35 inches wide 1 ft thick. The 12,000 I put in bus front tire compartment is 27 inch tall. I paid 1650 for the 24000 delivered. for two 9000 and one 12000 delivered the total was 1450. FWIW Bob

I just (attempted) to finish(ed) this project (well, almost) installed the mini-split, ran all the lines, installed the evaporators, mounted the outside unit on nice vibration isolators and a rubber pad and hooked everything up and had an AC tech come by to pull a vaccum and make sure there were no leaks. Then we dumped the freon and powered it up and it wouldn't work. The error we were getting told us that the evaporator units wouldn't communicate with the outside condensing unit. Upon further inspection we noticed that the inside models of the evaporator were a different model than the outside unit. I called the company that sold me the AC units and they said it was their mistake and comped the whole thing for me and said I could keep it. Nice and all but I still don't have AC. Very frustrating. Lots of story to tell but I won't post the novel here on the board. It will be on our website and I'll post the link here when it's up.

I'll post some pics tomorrow when I get time. The toughest thing for me was running the copper lines. If you are not down to a frame and are installing the lines, it can be really difficult to pull lines through cable trays with the insulation on them. Be careful not to kink the lines. Take the time to think through running the lines before you do it. If I did it again I think I might use an insulation tape/wrap onplain copper lines instead of buying pre-insulated lines. I had to run them twice cause I kind of rushed the first time and there was lots of cussing and bloody knuckles involved.

24,000btu outdoor unit 35 inches tall by 35 inches wide 1 ft thick. The 12,000 I put in bus front tire compartment is 27 inch tall. I paid 1650 for the 24000 delivered. for two 9000 and one 12000 delivered the total was 1450. FWIW Bob

Hi, Bob. Do you mind telling us where you bought your units? Did you find there tech material helpful in choosing your units? Did they offer good service? Thanks, Bruce H NC USA

As promised - here are some pics that I have on my phone of the Mini Split Install -

Here is the outside compressor unit being test fit in the bay -

The bay with the flooring before the walls went in -

The compressor installed, hookin up the electrical and need to clean up the electrical and copper lines -

Closeup of the vibration isolators. The isalators kept the footing 3/8" above the flooring. I bought a cheap rubber welcome mat to fit under the footing and it worked nicely -

The wooden brackets I cut to hold up the facing plate for the inside evaporators - If I did it again I would weld brackets but i was short on time and resources so I made them from wood. The evaporator is very lightweight maybe 15 pounds so heavy duty is not really needed -

Bottom facing mounted to the brackets -

The copper lines pulled through the dash to the front of the bus. There might be a slightly better way to do this but the 25' length of copper I had was just enough and this was the best route I could find that didn't involve adding additional length to the lines. Next bus I am running all the lines when I am down to the frame. Again - Remember that I am short on time and trying to get this done rather quickly so we can get on the road

The 1st evaporator test fit. I plan on eventually cutting in his & hers glove boxes in the space on either side of the evaporator.

Same pic a little further back. Those copper lines are now wrapped and look much nicer. I just don't have an updated picture of it. Will take a video later when I get home next week some time.

The bracket mounted and being test fit. The brackets are real light weight. Again the evaps are only about 15 pounds or so. Very lightweight.

A test fit of the evap over the fridge that services the bedroom areas -

A closeup of the insulated lines, electrical and drain being wrapped together -

Lines getting wrapped behind the refrigerator area -

AC tech hooking up the vaccuum -

A closeup of the connected lines -

Let me know if you have any questions or suggestions. I put a loop in the lines that go to the sleeping area to help absorb the shock. I'd have liked to have put a loop in the lines going to the front but there was not enough line left to do so and they have a little wiggle room, definitely not pulled tight.

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I'm looking for ideas on:

1. how best to run lines and what location

2. how best to mount the indoor unit

3. any other suggestions...pics as well.

Uemjg - Different buses will have options on where to best runthe lines. I ran the lines along the rest of the runs in the bus to the front and pulled them under the drivers area through where the spare tire is and up through the dash from underneath. That seemed like the only way I could do it with the 25' lines I had. If I had more time I would have pulled them section by setcion and sweated them together. Definitely easier when you have everything pulled apart which I did not.

Indoor unit is simple to mount. Just make sure you have enough clearance for airflow. Above and below. See manufacturer specs for dims.

I paid 1800 for a 2 zone unit with (2) 12k btu inside evaps. Because the manufacturer sent me mismatched outside and inside units that seemingly don't work together, they reimbursed my 1800 and now I have a system for free that is installed and would work fine if the evaps would communicate correctly with the condensor outside. According to the manufacturer it won't happen. Maybe if I could figure out a way to make it happen it would all be worth it

It cost me 300$ for the AC tech to come spend 3 hours hooking all the lines up, testing for leaks and pulling a vaccum and then troubleshooting why it wouldn't work.

-Sean

« Last Edit: April 24, 2013, 12:19:26 PM by Seangie »

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